Claims:I/We Claim
1. A system for evaluating temperature distribution along the length of the wire electrode in Wire Electric Discharge Machining (WEDM), wherein the system comprises application software installed on a communication device of a user to obtain temperature distribution along the length of the wire electrode.
2. The system as claimed in claim 1, characterized to develop a method for evaluating temperature distribution along the length of the wire electrode with different input parameters, wherein the parameters include but not limited to:
a) Thickness of work piece
b) Wire materials
c) Power input
d) Wire velocity and
e) Wire diameter
3. The method as claimed in claim 2, characterized to estimate thermal load on wire electrode in WEDM.
4. The method as claimed in claim 2, characterized to predict maximum temperature of wire electrode based on the input parameters in WEDM process.
5. The system as claimed in claim 1, characterized to develop a FORTRAN-95 program for the finite difference thermal (FDT) modeling.
6. The system as claimed in claim 1, characterized to be used for:
a) Different thickness of work piece
b) Different material of wire electrode
c) Different power input
d) Different wire velocity and
e) Different wire diameter
7. The system as claimed in claim 1, characterized to:
a) Reduces the setup time of the work-piece in WEDM
b) Reduces total breakdown time of WEDM
c) Reduces rejection rate of WEDM
d) Increases efficiency, effectiveness, availability and productivity of WEDM
, Description:We present here the research work related to an algorithm to develop a finite difference thermal (FDT) model for predicting maximum temperature and temperature distribution along the length of the wire electrode using FOTRAN-95.
FIELD OF INVENTION
Wire Electrical Discharge Machining (WEDM) is most popular non-traditional machining method used for machining difficult to machine materials like Titanium, nimonics, zirconium, etc. This machining process is widely used in critical manufacturing like aerospace, nuclear, missile, turbine, etc. The key benefit of WEDM process is to offer an effective solution over the conventional machining for machining difficult machine materials with complex, precise and accurate contours with intricate shapes in low volume and greater variety. WEDM can achieve high dimensional accuracy, repeatability and high surface finish as compared to mechanical machining at the cost of very slow machining rate. Increased production rate of WEDM has brought a lot of research effort since the introduction of this technology in 1960. However, when the WEDM is applied for vast mass production jobs, large economic benefit can be expected.
BACKGROUND OF INVENTION (PRIOR ART)
WEDM, in fact, is a thermal process. The high power density results in the erosion of a part of material from both the electrodes by local melting and vaporization. A better erosion rate from the work piece is a requirement for machining, on the contrary, the removal of the material from wire electrode leads to wire rupture and, hence, is undesirable. The wire rupture makes a negative impact upon the machining accuracy, productivity and stability of WEDM. Wire rupture leads to the breakdown of the WEDM, wastage of work pieces, and wastage of wire. As result of this it increases set up time, production time, labor cost, lead time and finally production cost. Hence the above conflict, to achieve higher erosion rate of the work piece and simultaneously reducing the wire breakage, sets a limit on the choice of machining conditions and parameters to avoid the wire breakage during WEDM process.
Various attempts have been made to develop the method and system for analyzing, optimizing and controlling machining systems for conventional and non-conventional machine. Different tools like finite element analysis, artificial intelligence, adaptive control, etc. are used to develop control program, methods and modeling for achieving the objective. The prior art related to analyzing, optimizing and controlling machining systems and wire breakage are discussed below.
In the prior art, U.S. Patent No. 7933679 relates with a machining process. This work concentrates to develop a method for analyzing and optimizing the machining process. In this work finite element analysis of work material and cutting tool interaction is performed. Using results of the finite element analysis, the developed mechanistic model of the process provide optimized parameters for improved rate of tool life and material removal rate. In this method, to analyze and optimize the machining process, so many mathematical and statistical tools have been used. The predetermined parameters are also not available for this method. Therefore, this method consumes a lot of time and gives no assurance of exact results in predicting the parameters.
The other prior art U.S. Patent No. 9317031 relates with an apparatus and a method for controlling machining systems by means of a control program. The apparatus includes data storage, where standard machining parameters are stored and which refers by the control program, a device for adjusting the machining parameters and a selectable machining target value. This method uses complex devices to control machining systems, so the device is not cost effective.
In other prior art, E.P. Patent No. 0359378 relates with an artificial intelligence system for adaptive control of machining for surface finish. This uses a mathematical model to adaptively control surface roughness; initializing the model essentially as a function of feed and subjected with initialized model to computerized estimation based on feed values and roughness taken from the last machined workpieces. Such model for the machining systems involved so many variables and was very complex for control of surface roughness in a machining application.
In other prior art, E.P. Patent No. 0723832 relates with a method of detecting wire electrode breakage during machining. The frequency of discharge is counted in a predetermined period of time, and a decision is made that whether the counted frequency exceeds a reference value or not. When the frequency does not exceed the reference value, the frequency of discharge is considered to decrease due to the occurrence of wire breakage, and the wire is judged to be not suitable for use.
In other prior art, U.S. Patent No. 4862095 relates with a method and apparatus for detecting breakage of wire electrode in an electric discharge machining. Breakage of the wire electrode is detected by sensing a change in current. For this, a detection power source used separately from the main power source. The reliability of this device is low and suffers various drawbacks thus there is a need to develop a reliable and cost effective device for wire breakage prognosis of WEDM.

EMPHASIZING THE ADVANTAGES OVER EXISTING INVENTIONS
With reference to the above prior arts, the present work fulfills the need to develop a system and a method for wire breakage prognosis of WEDM. The breaking of the wire electrode is also because of excessive thermal load which produces unwarranted heat on wire electrode. Hence, the thermal loading characterized as one of the prominent reasons for breakage, a thermal analysis is necessary. To capture this problem, the present invention concentrates to develop an algorithm based on finite difference thermal (FDT) model. This FDT model is applied for predicting the maximum temperature and temperature distribution along the length of the wire. The FDT model also expresses the significance of different WEDM process input parameters on maximum temperature and temperature distribution of wire electrode. The work-piece thickness, power input, wire velocity, and the wire diameter are having significant impact on the temperature distributions in the wire electrode in this FDT model, hence considered as the prime factor for this work.
OBJECT OF INVENTION
The present research work comprises the following specific objectives;
i. The principal object of the present invention is to develop the system to estimate thermal load on wire electrode in WEDM.
ii. It is yet another object of the present invention to evaluate temperature distribution along the length of the wire electrode in WEDM process.
iii. It is yet another object of the present invention is to develop a method to predict maximum temperature of wire electrode based on the input parameters in WEDM process.
iv. It is yet another object of the present invention to develop a FORTRAN-95 program for the finite difference thermal (FDT) modeling.
vi. It is yet another object of the present invention to identify the effect of input process parameters on temperature distribution in wire electrode of WEDM process using FDT model developed in FORTRAN-95.
vii. It is yet another object of the present invention to identify the effect of input process parameters on maximum temperature of wire electrode in WEDM process using FDT model developed in FORTRAN-95.
SUMMARY OF INVENTION/ STATEMENT OF INVENTION
The foremost objective of the present work is to develop an algorithm for FDT modeling of WEDM tool parameters using FORTRAN-95. High cutting rates and precision is necessary for WEDM to improve its productivity and high quality. WEDM is gaining more popularity among other non-conventional machining methods due to its wide application, high precision and used mostly in all manufacturing industries. In the WEDM process, the relationship between the input process parameters and output response parameters is obtained for various work piece thickness, wire material and power input values. This research work deals with the development of FDT models to calculate the output values of maximum temperature and temperature distribution along the length of the wire electrode relating to significant input process parameters of WEDM.
NOVALTY CLAIM IN THIS INVENTION:
Wire breakage is the one of the very important problems during WEDM process, will take place due to wrong projection of thermal load in wire electrode. The wire breakage affects the machining accuracy, productivity and stability of WEDM process. The novelty of this invention is to develop a finite difference thermal (FDT) model to obtain the temperature distribution along the length of the wire electrode, which was not considered in the prior works to arrest the wire breakage problem.
In this model the maximum temperature of wire electrode is calculated by giving the relevant process input parameters. This also gives the temperature distribution and estimate the thermal load on wire electrode. This helps to select the appropriate input process parameters of WEDM process and their values to arrest the wire breakage problem. This reduces the breakdown time associated with wire breakage during the machining on WEDM. As a result of this the set up time associated with wire breakage also reduces and this increases the production time of WEDM Machine. In any industry production time is a prominent factor which decides the productivity and profit of that industry. In this research work, the developed algorithm for finite difference thermal (FDT) modeling will reduce the set up time, total breakdown time and rejection rate of WEDM. At the same time this increases the quality, accuracy, efficiency, effectiveness, availability, productivity, overall equipment effectiveness and profit by predicting the temperature of wire electrode in a novel way.